1. Field of the Invention
The present invention relates to a supporting device for a substrate which supports a substrate to be treated (hereinafter referred to simply as "treated substrate") in a treating solution, and an anode formation (anodization) apparatus provided with it.
More specifically, the present invention relates to an apparatus for anodization of a crystalline silicon layer used in the field of formation technique of SOI (silicon on insulator) which is utilized in ULSI including Bi-CMOS device with both low dissipation power and high-speed operation, three-dimensional structure device including layered functional elements such as a sensor device, an arithmetical element, a memory, etc., or a high-voltage device such as a power transistor for electronic switching system, discharge printer, or plasma display, and in the field of micro machining technique, etc. Particularly, the present invention relates to an anodization apparatus used in producing porous silicon.
Here, "porous silicon" in the present invention means a crystalline silicon having a single crystal structure and at the same time having many pores therein.
Further, a term "crystalline silicon substrate" in the present invention means a silicon single crystal wafer having no pores, which is utilized in the field of semiconductor industries.